by Greg Toppo, @gtoppo, USA TODAY

by Greg Toppo, @gtoppo, USA TODAY

New research suggests that teacher absenteeism is becoming problematic in U.S. public schools, as about one in three teachers miss more than 10 days of school each year. The nation's improving economic picture may also worsen absenteeism as teachers' fears ease that they'll lose their job over taking too many sick days, researchers say.

First-ever figures from the U.S. Department of Education's Office for Civil Rights, compiled in 2012, also show that in a few states, nearly half of teachers miss more than 10 days in a typical 180-day school year.

Among them:

Rhode Island: 50.2%

Hawaii: 49.6%

Arkansas: 48.5%

New Mexico: 47.5%

Michigan: 45.6%

Schools serving larger proportions of African-American and Latino students are "disproportionately exposed to teacher absence," notes researcher Raegen Miller, who studied the federal survey data for the Washington-based Center for American Progress, progressive think tank.

Miller noted that providing substitutes for all of those absent teachers costs schools at least $4 billion a year - about 1% of schools' budgets. Absenteeism also lowers student achievement: A 2007 study by Duke University researchers estimated that for every 10 teacher absences, math achievement dropped by the same degree as if a school had replaced an experienced teacher with a novice one.

"Everybody basically accepts (that) teachers are the most important school-based resource affecting student achievement," said Miller, now at Teach For America. "Well, if that's true, we ought to be paying a lot more attention to the students' actual exposure to teachers."

Another researcher, Geoffrey Smith of Utah State University, said the economic downturn has actually had a positive effect on teacher absenteeism. Teachers, fearful of being fired over too many sick days, took fewer, he said. "Teachers didn't take any personal time because they didn't want to be let go," he said.

And cash-strapped school districts cut down on teacher training, pulling fewer teachers out of the class each week. The net effect, Smith said, was an uptick in the number of days that teachers stood in front of the class.

But both researchers said that's likely to change as the USA emerges from recession. Recent small-scale surveys from Smith show that the percentage of school districts with 10% or more teachers absent on a given day rose from 11.6% in 2010 to 25.5% in 2012.

School districts generally agree to personal leave benefits during contract negotiations with teachers' unions, and few superintendents are willing to risk bruising political battles over cutting teacher benefits, said Kate Walsh of the Washington, D.C.-based National Council on Teacher Quality.

"I don't see them taking this on," she said, adding that most superintendents have many more contentious issues to tackle. "They'll lose their jobs over trying to reduce (teacher) leave five days."

The Duke researchers have suggested paying teachers $400 more per year, but docking them $50 for each sick day they use. Walsh said superintendents should push to change school culture, persuading teachers to focus more on staying in school unless they're genuinely ill or experiencing an emergency.